What is Turnkey PCB Assembly?

Turnkey PCB Assembly is a printed circuit board (PCB) assembly solution that includes all the processes required to produce a finished PCB product. The term “turnkey” refers to a product that comes ready for the buyer to operate. In Turnkey PCB Assembly, all the aspects of PCB production from start to finish are handled by a single contractor or company. This includes processes like fabrication of the board, procurement of components to be placed on the board, the PCB assembly process and other testing or quality control processes that are required to give customers the final assembled board. It further includes sourcing raw materials and components, assembling, testing and taking the final product to the market. The PCBs are delivered to the customer fully assembled, programmed, and tested – ready to be integrated into products.

Usually, each step in the PCB assembly process is done separately or by different vendors. For example, one vendor would fabricate the board, then someone would be responsible for component procurement, and another company for PCB Assembly and testing of the final board. All this requires a significant amount of coordination. When most innovative small businesses and startups need to make PCBs, they often come across challenges when it comes to assembling those PCBs like the need to carry a large inventory and have an in-house team to create it.

Turnkey PCB Assembly offers a more efficient and cost-effective means of building and testing circuit boards for new products, with the shortest lead times possible. This cheap and effective solution eases the burden of small companies and startups to focus more on circuit board designs and lets the supplier handle the manufacture, tests, and transportation. Therefore, it reduces the lead times associated with production and enhances the management of resources for organizations.

Stages of Turnkey PCB Assembly:

Turnkey PCB assembly provides a seamless solution covering these stages:

• Design Support
  • Design for Manufacturing (DFM) analysis – Design for Manufacturability inputs to optimize assembly and efficiency.
  • BOM review – Ensure part selections meet cost, availability, and lifecycle needs.
  • Fabrication liaison – Smoothen handoff from PCB layout to fabrication.
• PCB Fabrication
  • This is the stage where a PCB design is transformed into a physical structure based on the specifications provided in the design package.

Click here to learn more about the PCB fabrication process.

• Supply Chain Management
  • Procurement – Sourcing and purchasing required components and bills of materials.
  • Vendor management – Coordinating with suppliers and tracking orders.
  • Inventory – Maintaining optimum inventory levels for production needs.
• SMT Assembly
  • Solder paste printing – Precisely deposit solder paste on pads.
  • Pick and place – High-speed component mounting using surface mount technologies.
  • Reflow soldering – Solder paste reflow in ovens to permanently bond components.
  • Inspection – Automated optical inspection (AOI) to check assembly quality.
• Post SMT Assembly
  • Conformal coating – Protect PCBs from environmental damage.
  • Box build – Enclosure integration and wiring.
  • End-of-line testing – validate assembly quality and functionality.
• Programming and Functional Test
  • ICT test – In-circuit test to verify shorts, opens, and values.
  • Boundary scan – Detect defects in BGA assemblies.
  • Firmware loading – Program firmware like power-on self-tests.
  • Functional test – Exercise system functions based on test specifications.
• Post Production Support
  • Repair and rework – Correcting component or design issues.
  • Upgrades – Component replacements, firmware updates, enhancements.
  • Warranty – Managing returns and replacing defective units.
  • End-of-life – Redesigns and replacements for obsolete parts.

Types of Turnkey PCB Assembly:

There are two types of Turnkey PCB assembly: 

• Partial Turnkey: In partial turnkey services, only part of the assembly process is outsourced. The technology developer or client retains responsibility for a portion of the supply chain and the supplier does the rest of the assembly. Usually, the client is in charge of obtaining, sorting, and packaging materials for delivery to the assembler. This is a viable option for those businesses that have the majority of the necessary parts in inventories and are seeking to cut down costs on some stages of the turnkey assembly.
• Full Turnkey: In full turnkey, the supplier bears the entire process including sourcing all components, assembly of the PCB, and delivery of the final product. The clients usually only have to provide the bill of materials, Gerber design files, product dimensions, packaging and shipping information.

Advantages of Turnkey PCB Assembly

Turnkey PCB assembly saves costs through more streamlined production processes. It also enables bulk purchasing and reduces errors in the assembly process and resulting delays. The provision of these services allows in-house management of the entire production cycle with minimal time wastage due to transport or coordination between vendors. Turnkey PCB assembly typically uses cloud-based software and powerful machinery to put together circuit boards more efficiently and at a greater volume than small and medium businesses can handle on their own. High product quality is assured by these automated systems that aim to provide perfect assembly and secure solder joints. Turnkey PCB assembly also enables early-stage design reviews to help detect and address issues before they become expensive, further improving efficiency. Leveraging the in-house capabilities and expertise of a turnkey PCB service provider results in improved quality of the final product. It also enables their clients to redirect internal resources to other areas like design, engineering, and software.